Chuck device of container, transportation device with the same, and chuck claw for the transportation device

ABSTRACT

A chuck device having a pair of arms rotatably supported by arm shafts and an operation member. One of the arms is provided with a roller shaft rotatable together with the arm about one of the arm shafts. The other arm is provided with an arm drive portion rotatable together with the arm. The arm drive portion is biased so as to press a second roller. Between the operation member and the roller shaft is provided a motion input mechanism for converting the motion of the operation member to rotational motion of the roller shaft about the arm shaft as the center of rotation. Between the roller shaft and the arm drive portion is provided an interlock mechanism that causes the arm drive portion to rotate about the arm shaft in conjunction with the motion of the roller shaft about the arm shaft as the center of rotation.

BACKGROUND OF THE INVENTION

The present invention relates to a chuck device for containers, aconveyor device equipped with the chuck device, and a chuck clawthereof.

An example of a conveyor device used with a beer bottle inspectiondevice or the like is a rotating star wheel device in which a discreferred to as a star wheel is formed with multiple pockets into whichbottles are fit. By supporting and releasing bottles from the pockets,bottles can be placed in appropriate positions along the rotation pathof the star wheel. Examples of bottle supporting structures of the starwheel device include one that uses a suction cup (e.g., Japaneselaid-open patent publication number Hei 11-106039) and one that uses apair of chuck claws that can open and close (e.g., Japanese laid-openpatent publication number Hei 10-7243).

Chuck-type star wheel devices are believed to be better suited forhigh-speed operations than suction-types, but designing a mechanicalchuck device requires simple mechanisms and flexibility in operations.Also, when multiple chuck devices are to be provided, it must bepossible to quickly attach and remove chuck claws to the chuck devicesor else the maintenance for the chuck claws becomes too complex.

SUMMARY OF THE INVENTION

The present invention provides a chuck device and a conveyor deviceusing the chuck device that can improve the degree of freedom involvedin operation, that can provide a simplified structure, and that can besuitable for higher conveyor speeds. The present invention also providesa chuck device with a removable chuck claw, a chuck claw used by thedevice, and a conveyor device that uses the chuck claw and the chuckdevice.

According to the present invention a chuck device includes: supportingstructure; a pair of arms rotatably supported on the supportingstructure by way of a pair of arm shafts, chuck claws for grasping acontainer disposed on ends of the pair of arms that open and close intandem with rotation around the arm shafts; and an operation membercapable of being operated on externally. Inward from the pair of arms isdisposed a first drive section capable of integrally rotating around thearm shaft of a first arm and being integral with the first arm, and asecond drive section disposed further toward the end of the arm than thefirst drive section and capable of rotating integrally around the armshaft of a second arm and being integral with the second arm. Biasingmeans biases the pair of arms around the arm shafts in a direction ofclosing the ends of the arms. A motion input mechanism is disposedbetween the operation member and the first drive section and convertsexternal motion accompanying operation of the operation member to arotation motion of the first drive section centered around the armshaft. A coupling mechanism is disposed between the first drive sectionand the second drive section and converts rotational motion of the drivesection around the arm shaft to a rotational motion of the second drivesection around the arm shaft.

With this chuck device, when the operation member is operated and thefirst drive section is rotated around the arm shaft, the second drivesection also rotates around the arm shaft so that the pair of arms pivotto open and close the chuck claws. Since the motion of the operationmember is first transmitted from the first drive section to the armthereof, and this rotation motion is transmitted to the second drivesection by way of a coupling mechanism, it is possible to define theoperations of each arm by changing the way the motions are converted.For example, it is possible to change how the second arm moves withoutchanging how the first arm moves in response to operation of theoperation member, or the operation of the first arm in response tooperation of the operation member can be changed while adjusting thecoupling mechanism to cancel out this change so that the operation ofthe second arm does not change. Of course, the pair of arms can beoperated symmetrically as well.

In the first chuck device of the present invention, the motion inputmechanism uses a cam mechanism to convert a motion of the operationmember to rotation motion of the first drive section. By using the cammechanism, the element opposing the cam surface (the cam driven element)can simply be pressed against it, eliminating the need for connectingthe elements, e.g., with a linking mechanism. Thus, the structure issimplified and assembly and disassembly can be performed easily.

According to another aspect, the cam mechanism of the motion inputmechanism is equipped with an arm drive cam supported by the supportingstructure to allow rotation around a cam axis line parallel to the armshaft, a cam surface being formed on an outer perimeter of the arm drivecam. The arm drive cam is disposed opposite from the second drivesection relative to the first drive section. The arm drive cam isrotated by external operation of the operation member. As the arm drivecam rotates, the cam surface of the arm drive cam moves back and forthbetween a position where the first drive section is pushed out towardthe second drive section and a position where the first drive section isretracted to an opposite side from the second drive section.

In this case, the arm drive cam rotates back and forth according to thedirection in which the operation member is operated, and the first drivesection is driven in the direction toward the second drive section oraway from the second drive section. Since the second drive section ispushed against the first drive section by biasing means, the seconddrive section rotates around the arm shaft in tandem with the firstdrive section regardless of which direction the first drive section isdriven.

It is also possible for a first roller that comes into contact with thecam surface of the arm drive cam to be disposed on the first drivesection. Using the roller can reduce the friction resistance at the camsurface, just making the mechanism operate more smoothly. Furthermore, aroller shaft parallel to the arm shaft can be disposed on the firstdrive section. On the roller shaft, there can be disposed a first rollercoming into contact with the cam surface of the arm drive cam, and asecond roller coming into contact with the second drive section.

A support section can be disposed on the cam surface of the arm drivecam to support the first drive section at a position pushed out towardthe second drive section. By providing this type of support section,when the first drive section is pushed out toward the second drivesection by the biasing mechanism, the supporting force opposing thebiasing mechanism force does not need to be applied continuously tomaintain the arm drive cam at the same position. Thus, restrictions onthe design of the mechanism for operating the operation member can berelaxed. For example, when the biasing mechanism biases the chuck clawsin the closing direction, the absence of a supporting section wouldrequire keeping the chuck claws open by continuously guiding theoperation member with a cam groove or the like so that the supportingforce continues to be applied to the operation member. However, if thesupport section is provided, the first drive section can be guided tothe support section to keep the arm drive cam and the first drivesection at a fixed position without applying any force to the operation,thus allowing the chuck claws to be kept open. Thus, the mechanism foroperating the operation member is simplified. Providing a cam groove orthe like along the conveyor path to support the operation member leadsto a larger cam and increases costs. In particular, if a cam groove isused, complex cleaning tasks are required to prevent clogging of thegroove. Providing a support section on the cam surface eliminates thisproblem.

The coupling mechanism can use a cam mechanism to convert rotationmotion of the first drive section to rotation motion of the second drivesection. In this case, the use of the cam mechanism eliminates the needto connect the first drive section and the second drive sectiontogether. Thus, the structure is simplified and assembly and disassemblyis made easy. In particular, it is preferable to have both the motioninput mechanism and the coupling mechanism use cam mechanisms. In onepreferable form of the cam mechanism of the coupling mechanism, a camsurface that comes into contact with the first drive section is disposedon the second drive section. By changing the shape of the cam surface,the manner in which the second arm works in response to the first armcan be changed.

The biasing mechanism can include one or more springs disposed betweenthe support means and the second arm and biasing the second arm so thatthe chuck claws are biased in a closing direction. Simply providingbiasing means between the arms will not restrict the arms to turn in thesame direction around the arm shafts. When this type of motion takesplace, the first drive section and the second drive section aredisplaced away from each other, and the coupling of the arms istemporarily lost, allowing the arms to move freely. However, in theabove structure where the biasing mechanism is extended between thesupport structure and the second arm, the second drive section can bepressed toward the first drive section regardless of how the arms areoperating.

The biasing means can be torsion coil springs on each of the pair of armshafts to bias the pair of arms so that the ends are biased in a closingdirection. By providing torsion coil springs on the arm shaft, the pairof arms can be biased symmetrically, and the need to extend the armsback past the arm shaft is eliminated. As a result, the structure of thearms is simplified, and the space behind the arms can be usedeffectively.

Furthermore, in the structure in which the arm drive cam is disposed onthe cam mechanism as described above, it is possible to have torsioncoil springs disposed as biasing means on each of the pair of arm shaftsto bias the pair of arms so that the ends are biased in a closingdirection; and both ends of a cam shaft can rotatably support the pairof arm shafts and the arm drive cam can be supported by the supportingstructure. As a result, the arm shaft and the cam shaft of the arm drivecam can be firmly supported so that these elements are prevented fromflexing.

The first conveyor device according to the present invention includes:the first chuck device according to the present invention; and a mobilebody moving the support structure of the chuck device along apredetermined conveyor path. With this type of conveyor device,containers can be conveyed by supporting the container with the chuckdevice while the mobile body moves. Multiple chuck devices can bedisposed along the conveyor path of the mobile body. For example, in astar wheel conveyor device, chuck devices can be disposed along theouter perimeter of a rotating wheel and oriented outward, i.e., with thechuck claws oriented toward the outer perimeter side. Furthermore, anoperation section can be provided on the conveyor path that operates anoperation member by coming into contact with the operation member inresponse to movement of the chuck device. By operating the operationmember using the operation section, the chuck claws can be closed oropened at a predetermined position on the conveyor path, so that acontainer can be retrieved or deposited.

The operation section can include a movable section capable of movingbetween an active position, where the operation section is in contactwith the operation member and operates the operation member, and astand-by position away from the operation member. In this case, byswitching the active unit between an active position and a stand-byposition, it is possible to change whether or not the chuck clawsoperate at the positions where the active units are installed.Furthermore, the movable section can be driven by an electrical servomotor between the active position and the stand-by position. By using aservo motor, accurate operations can be performed at high-speeds. Thus,the invention can handle high-speed conveyors better.

A second chuck device according to the present invention provides achuck device wherein a chuck claw is removably mounted on an end of anarm driven to perform a grasping action. A cylindrically indentedbearing surface is disposed on the arm. A holding piece equipped with acylindrical outer perimeter surface curved along the bearing surface isdisposed on the bearing surface using tightening mechanism. Anattachment base curved along the bearing surface and capable of beinginserted between the support piece and the bearing surface is disposedon the chuck claw.

With this chuck device, the tightening applied by the tighteningmechanism on the support piece can be loosened to enlarge the gapbetween the bearing surface and the support piece, the attachment baseof the chuck claw can be inserted into the gap, and the support piececan be tightened against the bearing surface to have the support pieceand the bearing surface support the interposed chuck claw. Since thebearing surface and the support piece have cylindrical surfaces, thechuck claw is prevented from rotating by the bearing surface and thesupport piece. As a result, further operations to prevent rotation ofthe support piece and the chuck claw are not needed. For example, evenif a single bolt is used as the tightening mechanism, the chuck clawwill not rotate around the bolt. Thus, according to the second chuckdevice of the present invention, the chuck claw can be easily attachedand removed.

In the second chuck device of the present invention, it is preferablefor the tightening mechanism to be a bolt. Since there is no need tostop rotation, a single bolt used as the tightening mechanism for asingle support piece is sufficient. When a bolt is used, it ispreferable for a slit to be formed on the attachment base of the chuckclaw to allow the bolt to pass through. By passing through the boltthrough this type of slit, the attachment base can be inserted deeplyinto the gap between the bearing surface and the support piece withoutremoving the bolt. Thus, the chuck claw can be more easily attached andremoved.

It is also possible to have a chuck bearing disposed on the arm toreceive reaction generated on the chuck claw during the grasping action.The bearing surface may be formed to connect with a side of the chuckbearing section that comes into contact with the chuck claw. The boltcan be set up to attach to the bearing surface in such a direction that,going toward a rear end of the arm, the bolt extends from the bearingsurface toward a back surface relative to a side of the arm in contactwith the chuck claw. With this structure, an adequate threading depthfor the bolt can be provided even if the chuck bearing is thin.

Furthermore, it is also possible to have an arm shaft rotatablysupporting the arm to be disposed behind the bearing surface, and tohave the bolt screwed in between the bearing surface and the arm shaft.As a result, a deep threading depth for the bolt can be provided whileavoiding the arm shaft.

It is also possible to have left and right arms, a bearing surfacedisposed inward from each arm, the bolts passing through the supportpieces from inward of the arms being screwed into the arm, and slitsbeing disposed at ends of the chuck claws to allow insertion of a toolused to manipulate the bolts. With this structure, the slit toward theend of the chuck claw can be used to insert a tool such as a wrench.This allows a bolt hidden between the chuck claws to be easily andadequately manipulated.

It is also possible to have a spring mechanism disposed between thesupport pieces attached to the bearing surfaces of the arms to draw thesupport pieces toward each other. In this case, loosening the bolt willresult in the support piece being pulled by the spring mechanism awayfrom the bearing surface. As a result, the attachment base of the chuckclaw can be easily pulled out from the gap between the support piece andthe bearing surface.

The chuck claw can be formed from various materials, but it ispreferable for the chuck claw to be metal. If metal is used, the chuckclaw can be made thin while still maintaining adequate strength. Theelasticity of the chuck claw can be used to improve the ability of thechuck claws to handle different shapes and sizes of the object to begrasped. Also, by making the chuck claw thin, when multiple chuckdevices are used, the pitch between the chuck devices can be reduced,thus conserving space.

In the chuck claw of the present invention, a grasping sectionperforming grasping actions is formed on a first end; and an attachmentbase curved to form a cylindrical surface is formed on a second end.This type of chuck claw can be used suitably in the second chuck deviceof the present invention.

In the chuck claw of the present invention, it is also possible to havea slit extending in a perimeter direction of a cylindrical surfacedefined by the attachment base disposed on the attachment base. Also, aslit that divides the grasping section along a direction of an axis of acylindrical surface defined by the attachment base can be formed on thegrasping section.

Furthermore, a second conveyor device according to the present inventionincludes: a mobile body capable of pivoting around a predeterminedcenter; and a chuck device. A plurality of the chuck devices aredisposed along an outer perimeter of the mobile body. With this type ofconveyor device, effective use can be made of the advantage of the chuckdevice of the present invention in that the chuck claw can be easilyattached and removed.

The above, and other objects, features and advantages of the presentinvention will become apparent from the following description read inconjunction with the accompanying drawings, in which like referencenumerals designate the same elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan drawing of a starter wheel device in which chuckdevices of the present invention are used.

FIG. 2 is a side-view drawing of a chuck device from FIG. 1.

FIG. 3 is a cross-section drawing along the line III-III in FIG. 2.

FIG. 4 is a drawing of the chuck device as seen from the arrow IV inFIG. 2.

FIG. 5 is a cross-section drawing along the line V-V in FIG. 3.

FIG. 6 is a cross-section drawing along the line VI-VI in FIG. 5.

FIG. 7 is a drawing showing the chuck device as seen from the arrow VIIin FIG. 2.

FIG. 8A is a cross-section drawing along the line VIII-VIII in FIG. 5,with the chuck bearings closed.

FIG. 8B is a cross-section drawing along the line VIII-VIII in FIG. 5,with the chuck bearings open.

FIG. 9 is a cross-section drawing along the line IX-IX in FIG. 5.

FIG. 10 is a simplified drawing as seen from the end of the chuckdevice.

FIG. 11 is a perspective drawing of a chuck claw.

FIG. 12 is a detail drawing of the area around the entry position inFIG. 1.

FIG. 13 is a detail drawing showing a bottle not being deposited at thefirst exit position in FIG. 1.

FIG. 14 is a detail drawing showing a bottle being deposited at thefirst exit position in FIG. 1.

FIG. 15 is a detail drawing showing a bottle being deposited at thesecond exit position in FIG. 1.

FIG. 16 is a cross-section drawing along an arm shaft in anotherembodiment that uses a torsion coil spring as a biasing mechanism.

FIG. 17 is a drawing showing a chuck device as seen from arrow XVII inFIG. 16.

FIG. 18 is a plan drawing of a chuck device from FIG. 16.

FIG. 19 is a cross-section drawing along the line XIX-XIX from FIG. 16.

FIG. 20 is a cross-section drawing of the chuck device from FIG. 16corresponding to the view in FIG. 5.

FIG. 21 is a drawing showing another example of a tightening mechanismfor a support piece.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a plan drawing of a star wheel for conveying beer bottles inwhich a chuck device of the present invention is implemented. A starwheel device 1 is formed as an exit star wheel device, e.g., aninspection device used to inspect bottles BT. Bottles BT are received atan entry position P1 from a separate star wheel device 2 that supportbottles BT being inspected. The bottles BT are sent out from a firstexit position P2 or a second exit position P3 to a first conveyor 3 or asecond conveyor 4. Multiple chuck devices 5, . . . , 5 for supportingthe bottles BT are disposed along the outer perimeter of the star wheeldevice 1 at a fixed pitch.

As shown in FIG. 2, the chuck device 5 is equipped with a base 10 and achuck claw 50 for grasping the bottle BT. The base 10 is secured to theouter perimeter of a wheel (moving body) 6 of the star wheel device 1using a securing structure 7 such as a bolt. The wheel 6 is rotatedaround a wheel center Cw by a drive device, not shown in the figure, ina predetermined rotation direction (indicated by arrow R in FIG. 1).Thus, the chuck devices 5 are also rotated around the wheel center Cwalong with the wheel 6.

A guide 13 is attached to the base 10. The guide 13 is equipped with aguide surface 13 a curved along the outer perimeter of the bottle BT.Taking into account the tolerance of the diameter of the bottle BT to begrasped by the chuck device 5, the curvature radius of the guide surface13 a of the guide 13 is set slightly larger than the radius of thebottle BT. If the chuck device 5 is set up to handle bottles BT ofmultiple sizes, the guide 13 is either set up for the bottles BT withthe maximum diameter or guides 13 can be set up according to thespecific type of bottle BT. In this embodiment, the guide 13 can beomitted if the chuck claw 50 can adequately constrain the bottles BT.

As shown in FIG. 3 through FIG. 6, left and right arms 15L, 15R areattached on the upper surface side of the base 10 so that it can rotatearound upwardly extending arm shafts 16L, 16R. The arm shafts 16L, 16Rare disposed in symmetrical positions relative to a reference line CLconnecting the center Cb of the bottle BT and the wheel center Cw (seeFIG. 1). The upper ends of the arm shafts 16L, 16R are connected by atop plate 14 and bolts 14 a. As shown in FIG. 2, the guide 13 isattached to the top plate 14 as well. In this embodiment, the “left” and“right” of the chuck device 5 is defined in terms of when the chuckdevice 5 is viewed along the reference line CL from the wheel center Cwside. Thus, the side above the reference line in FIG. 3 and the side tothe right in FIG. 4 correspond to the left side of the chuck device 5.

As shown in FIG. 3, FIG. 5, and FIG. 6, a roller shaft 17 is attached atthe inside of the arm 15L and parallel to the arm shaft 16L. A firstroller 18 is rotatably attached at the outer perimeter of the lowersection of the roller shaft 17. A bracket 20 is secured using a bolt 20a to the lower surface side of the base 10. A cam shaft 21 extending upand down is rotatably attached to the bracket 20. The cam shaft 21 isdisposed along the reference line CL and away from the roller shaft 17toward the wheel center Cw (to the left in FIG. 5). As shown in FIG. 7,the lower end of the cam shaft 21 projects below the base 10, and a camdrive lever 22 is attached to the projected section so that it rotatesintegrally with the cam shaft 21. A cam drive roller 23 is attached tothe end of the cam drive lever 22 as an operating member that allows thecam drive roller 23 to rotate around a support shaft (bolt) 24.

As shown in FIG. 5, an arm drive cam 25 is attached to the upper end ofthe cam shaft 21 so that it rotates integrally with the cam shaft 21. Asshown in detail in FIGS. 8A and 8B, the arm drive cam 25 is equippedwith a cam surface 26 that comes into contact with the first roller 18.The cam surface 26 is formed by smoothly connecting a first cavity 26 a,a second cavity 26 b serving as a support section, and a projection 26 cdisposed therebetween. The curvature radii of the cavities 26 a, 26 bare the same as or slightly greater than the radius of the first roller18. The distance from the rotation center of the cam shaft 21 to the camsurface 26 is shortest at the bottom of the first cavity 26 a and isgreatest near the boundary between the projection 26 c and the secondcavity 26 b. The distance from the rotation center of the cam shaft 21to the bottom of the second cavity 26 b is adequately larger than thedistance from the rotation center of the cam shaft 21 and the bottom ofthe first cavity 26 a.

As shown in FIG. 3 through FIG. 9, an arm drive section (second drivesection) 28 is disposed on the right arm 15R so that it faces the camshaft 21. A cam surface 30 is disposed on the arm drive section 28. Asecond roller 31 is rotatably attached to the outer perimeter of theroller shaft 17 at a position aligned with the cam surface 30. A post 32is disposed behind the left arm 15L, and the top plate 14 is secured tothe upper end of the post 32 (see FIG. 5). As shown in FIG. 9, a springbearing cavity 32 a is disposed on the post 32, and a coil spring 33 isattached in a compressed state between the spring bearing cavity 32 aand a spring bearing cavity 15 a formed at the back end side of theright arm 15R. The post 32 is connected to the base 10 by way of the topplate 14 and the arm shafts 16L, 16R and serves as part of thesupporting structure for the arms 15L, 15R. As a result, the biasingmechanism, in the form of the spring 33, disposed between the supportingstructure pushes the chuck claw 50 of the arm 15L in the closingdirection. A bolt 34 is attached to the post 32 to guide the innerperimeter of the coil spring 33.

As shown in FIG. 3, a coil spring 35 is attached in a compressed stateas a separate biasing mechanism between spring bearings 15 b, 15 c ofthe arms 15L, 15R below the coil spring 33. The repulsion of the coilsprings 33, 35 bias the arms 15L, 15R around the arm shafts 16L, 16R sothat chuck bearings 40 at the ends of the arms are brought toward eachother (i.e., in the direction toward the reference line CL). As aresult, the cam surface 30 is pushed into the second roller 31, and thefirst roller 18, which is co-axial to the second roller 31, is pushedinto the cam surface 26 of the arm drive cam 25. Thus, the first roller18 and the second roller 31 move around the arm shaft 16L in tandem withthe rotation of the arm drive cam 25, and this is accompanied by therotation of the arm 15L around the arm shaft 16L. Also, the arm drivesection 28 rotates around the arm shaft 16R in tandem with the movementof the second roller 31, and this causes the arm 15R to also rotatearound the arm shaft 16R.

As shown in FIG. 8A, when the first roller 18 is engaged with the firstcavity 26 a of the cam surface 26, the cam shaft 21 is positionedbetween the arm shafts 16L, 16R and on the reference line CL, and thechuck bearings 40 at the ends of the arms 15L, 15R are closed. As shownin FIG. 8B, when the arm drive cam 25 rotates so that the first roller18 moves toward the second cavity 26 b of the cam surface 26, the camshaft 21 is pushed toward the outer perimeter of the wheel 6, and thearms 15L, 15R rotate around the arm shafts 16L, 16R so that the chuckbearings 40 are opened. When the first roller 18 moves past theprojection 26 c and engages with the second cavity 26 b, the firstroller 18 stays engaged with the second cavity 26 b, working against thecoil springs 33, 35, which provide bias in the direction of closing thearms 15L, 15R. However, when the first roller 18 applies enough rotationmoment to the arm drive cam 25 to go past the projection 26 c, thesprings 33, 35 cause the cam 25 to rotate to a position where the firstcavity 26 a and the first roller 18 engage.

In the description below, the position of the arm drive cam 25 shown inFIG. 8A will be referred to as the constrained position and the positionshown in FIG. 8B will be referred to as the released position. The camdrive roller 23 shown in FIG. 7 is associated with the arm drive cam 25in a manner such that it is retracted toward the wheel center Cw whenthe arm drive cam 25 is in the constrained position, and is displacedtoward the outer perimeter side of the wheel 6 when the arm drive cam 25is in the released position.

Next, the attachment structure for the chuck claws 50 will be described.As shown in FIG. 3 through FIG. 9, bearing surfaces 41 are formed ascylindrical indentations on the inner surface sides of the base ends ofthe chuck bearings 40 of the arms 15L, 15R. A threaded hole 42 is formedon each of the bearing surfaces 41. The threaded holes are formeddiagonally into the arms 15L, 15R so that, going from inside to outsideof the arms 15L, 15R, the threaded holes 42 are recessed radiallyinward. As shown in FIG. 10, a cylindrical support piece 43 is attachedto the bearing surface 41 by threading a single bolt 44 from the insideof the arms 15L, 15R. The chuck claws 50 are mounted to the ends of thearms 15L, 15R using these support pieces 43. Coil springs 45, 45,serving as spring mechanisms, are stretched out between the upper endsand the lower ends of the support pieces 43. FIG. 9 shows the coilspring 45 at the upper end of the support pieces 43. A section of thelower coil spring 45 is shown in FIG. 3.

The chuck claws 45 are formed from by metalworking on thin, highly rigidsheets such as stainless steel. As shown in FIG. 11, the chuck claw 50is equipped with a grasping section 51 for grasping the bottle BT and anattachment base 52 for attachment to the arms 15L, 15R. The attachmentbase 52 is curved so that it extends along the bearing surface 41, and aslit 53 is formed at roughly the center of its vertical axis and extendsparallel the perimeter of the attachment 52. A slit 54 is formed in asimilar manner on the side of the grasping section 51 as well. The slit54 divides the grasping section 51 into upper and lower sections. Theslit 54 on the grasping section 51 side extends across the center lineof the threaded hole 42, and the width of the slit 54 is set to be largeenough to allow insertion of a tool to manipulate the bolt 44 (e.g., ahex wrench). As indicated by the dotted lines in FIG. 11, a stoppingmember 50 a may be disposed on the inner surface of the grasping section51.

The attachment of the chuck claws 50 will now be described. The bolt 44is loosened so that a gap somewhat larger than the thickness of thechuck claw 50 is formed between the support piece 43 and the bearingsurface. The attachment base 52 is inserted in the gap between thesupport piece 43 and the bearing surface 41 while turning the chuck claw50 along the bearing surface 41. The bolt 44 is passed through the slit53. The bolt 44 is then tightened so that the attachment base 52 of thechuck claw 50 is firmly clamped between the bearing surface 41 and thesupport piece 43. The chuck claw 50 can be removed by loosening the bolt44 and pulling out the attachment base 52 of the chuck claw 50 frombetween the support piece 43 and the bearing surface 41.

With the chuck device 5 described above, the operations of the arms 15L,15R can be varied by changing the shape of the cam surface 30. In thisexample, the shape of the cam surface 30 is set up so that the chuckclaws 50 move symmetrically relative to the reference line CL. However,it is also possible to assign different operations to the chuck claws50, 50, e.g., to have one of the chuck claws 50 open first, by changingthe shape of the cam surface 30.

As shown in FIG. 1, operation sections 60, 70, 80 are disposed at entryposition P1 and exit positions P2, P3, respectively. As shown in FIG.12, a cam block 61 is disposed on the operation section 60 at the entryposition P1. The cam block 61 is secured at a fixed position relative tothe rotation of the wheel 6 by being attached to a fixed section, e.g.,the base, of the starter wheel device 1. A cam surface 61 a facing thewheel center Cw is formed on the cam block 61. When the arm drive cam 25of the chuck device 5 is in the free position, the cam surface 61 acomes into contact with the cam drive roller 23, and, taking advantageof the rotation of the wheel 6 to a position where the first roller 18can disengage from the second cavity 26 b of the arm drive cam 25, thecam drive roller 23 is sent toward the wheel center Cw.

As shown in FIG. 13 and FIG. 14, a rotor 71 is disposed as a movablesection of the operation section 70 at the exit position P2. The rotor71 is disposed so that it can rotate around a vertical axis, and on theouter perimeter thereof are formed a pair of arms 71 a, 71 a that cancome into contact with the cam drive roller 23. Also, as shown in FIG.1, the rotor 71 is connected to an output shaft 73 a of a servo motor 73by way of a transmission mechanism 72. A belt-type transmission deviceor the like is used for the transmission mechanism 72. Driven by theservo motor 73, the rotor 71 rotates between an active position, wherethe arm 71 a is projected toward the chuck device 5 (FIG. 14), and astand-by position, where the arms 71 a are retracted away from theactive position toward the wheel center Cw (FIG. 13). As shown in FIG.14, when the rotor 71 is at the active position, the arm 71 a comes intocontact with the cam drive roller 23 when the arm drive cam 25 of thechuck device 5 is in the constrained position. The rotation of the wheel6 up to when the arm drive cam 25 moves to the free position is used tosend the cam drive roller 23 toward the outer perimeter of the wheel 6.When the rotor 71 is at the stand-by position, the arm 71 a is retractedfurther toward the wheel center Cw than the cam drive roller 23regardless of the position of the arm drive cam 25.

Next, the operations of the starter wheel device 1 presented above willnow be described. First, the chuck devices 5 are brought out one by oneto the entry position P1 of the starter wheel device 1 as the wheel 6rotates. The arm drive cam 25 is in the free position in front of theentry position P1, and the chuck claws 50 are opened. When the chuckdevice 5 is brought to the entry position P1 by the wheel 6, the camdrive roller 23 comes into contact with the cam surface 61 a and ispushed toward the wheel center Cw. As a result, the first roller 18disengages from the second cavity 26 b of the arm drive cam 25 and thearm drive cam 25 returns to its constrained position. This closes thechuck claws 50. In tandem with the closing of the chuck claws 50, thebottle BT is passed on from the star wheel device 2 to between the chuckclaws 50, and the bottle BT is grasped by the chuck claws 50, 50 (seeFIG. 12).

As the wheel 6 rotates, the bottle BT grasped by the chuck claws 50 isfirst conveyed to the first exit position P2. At the first exit positionP2, the rotor 71 is kept at the stand-by position shown in FIG. 13. Ifthe bottle BT is a bottle BT that should be sent out to the firstconveyor 3, the servo motor 73 is driven to move the arm 71 a to theactive position shown in FIG. 14 when the cam drive roller 23 of thechuck device 5 is to be sent out to the first exit position P2. As aresult, the cam drive roller 23 comes into contact with the arm 71 a andis pushed toward the outer perimeter, causing the arm drive cam to bemoved from the constrained position to the free position. Thus, thechuck claws 50 open and the bottle BT is sent out to the first conveyor3. After the bottle BT is sent out, the rotor 71 returns to the stand-byposition before the roller 23 reaches the rotation range of the arm 71a.

If the bottle BT sent to the first exit position should not be sent outto the first conveyor 3, the servo motor 73 is not activated and therotor 71 stays in the stand-by position. Thus, the cam drive roller 23of the chuck device 5 holding the bottle BT is not able to come intocontact with the arm 71 a, and the arm drive cam 25 is kept in theconstrained position. Thus, as shown in FIG. 13, the bottle BT thatshould not be sent out is not released from the chuck claw 50, passes bythe first exit position P2 and heads toward the second exit position P3.

As shown in FIG. 15, the cam surface 81 a comes into contact with thecam drive rollers 23 of the chuck devices 5 sent one by one to thesecond exit position P3 as the wheel 6 rotates, and every arm drive cam25 is switched from the constrained position to the release position. Asa result, the chuck claws 50 are always opened at the second exitposition P3. Thus, the bottles BT transported to the second exitposition P3 are sent out to the second conveyor 4.

With the star wheel device 1 of this embodiment as described above, thebottles BT can be selectively sent out to the first exit conveyor 3 orthe second exit conveyor 4 by switching the position of the rotor 71installed at the first exit position P2. For example, when the bottlesBT and their contents are inspected before the star wheel device, therotor 71 can be switched from the stand-by position to the activeposition when a bottle BT that passed the inspection reaches the firstexit position P2. This allows the good products that have passed theinspection to be sent to the first exit conveyor 3 while the defectiveproducts that did not pass the inspection are sent to the second exitconveyor 4.

On the other hand, if the rotor 71 is kept in the stand-by position whena bottle BT that has passed the inspection is sent to the first exitposition P2 and the rotor 71 is put in the active position when a failedbottle BT is sent to the first exit position P2, the defective productsthat did not pass the inspection can be sent out to the first exitconveyor 3 and the good products that passed the inspection can be sentout to the second exit conveyor 4. More specifically, the rotor 71 canbe kept in the stand-by position by default so that the chuck claws 50are kept open at the first exit position P2. At the second exit positionP3, the cam block 81 can be used to open the chuck claws 50 to releasethe bottle BT,. When there is a need to separate the bottles BT that didnot pass the inspection or the like, the rotor 71 can be switched to theactive position to open the chuck claws 50 when the chuck device 5holding the bottle BT reaches the first exit position P2. The rotor 71then needs to return to the stand-by position before the next bottle BTreaches the first exit position P2.

The star wheel device 1 and the chuck device 5 of this embodimentprovide the following operations and advantages.

(1) Everything from the cam drive roller 23 of the chuck device 5 to thecam surface 30 is completely mechanical. This provides superiorresponsiveness and reliability in the opening and closing actions of thechuck claws 50 and allows the wheel 6 to be operated at higher speeds.

(2) Since the cam surfaces 26, 30 are pressed against the opposing(driven) rollers 18, 31 using the coil springs 33, 35, there is no needto mechanically connect the arm drive cam 25 to the arms 15L, 15R, whichare driven by the arm drive cam 25. This makes assembly and disassemblyeasy. Also, the cam surfaces 26, 30 are placed into contact with therollers 18, 31, so friction resistance is reduced and operations can bemade smoother. In the present invention, it is possible to convert therotation of the cam shaft 21 using a linkage mechanism to open and closethe arms 15L, 15R. However, if a linkage mechanism is to be used,connections must be made between the links themselves and the links tothe arms and the like, increasing the number of assembly steps.

(3) Since the second cavity 26 b is formed on the cam surface 26 to keepthe arm drive cam 25 in the release position in opposition to the coilsprings 33, 35, keeping the chuck claws 50 open does not require, on thestar wheel device 1 side, keeping the cam drive roller 23 continuouslyat a position corresponding to the release position of the arm drive cam25. Thus, to keep the chuck claws 50 in an open state, the rotor 71 andthe cam 81 need only push the roller 23 in until the first roller 18goes past the projection 26 c and enters the second cavity 26 b, and thecam 81 and the like do not need to keep pushing the roller 23 once thearm drive cam has switched to the release position. If this type ofself-supporting feature were not present for the arm drive cam 25, itwould be necessary to design the cam 61 so that, first, the chuck claws50 are opened at the entry position P1, and then the chuck claws 50 areclosed when the bottle BT is received. This would make the cam 61 morecomplicated.

(4) In order to rotationally bias the arms 15L, 15R in the direction ofclosing the chuck claws 50, it is necessary to provide the coil spring35 between the arms 15L, 15R and also to provide the coil spring 33between one of the arms 15R and the side on which the arms 15L, 15R aresupported (the post 32), thus biasing the arm 15R in the direction thatpushes the cam surface 30 thereof against the second roller 31. If onlythe coil spring 35 were to be provided, the arms 15L, 15R could pivotaround the arm shafts 16L, 16R clockwise (in the view in FIG. 3),disengaging the second roller 31 and the cam surface 30, and leading toinstability in the chuck claws 50, 50. However, by using the coil spring33 to bias the arm 15R around the arm shaft 16R in the counter-clockwisedirection, the arm 15R is prevented from pivoting in this manner, andthe contact between the cam surface 30 and the second roller 31 can bemaintained.

(5) Since the servo motor 73 is used to drive the rotor 71, the rotor 71can be operated at high speeds and accurately, thus allowing theinvention to handle high speeds for the wheel 6.

(6) Furthermore, the attachment structure for the chuck claws 50according to this embodiment provides the following advantages. First,since the chuck claw 50 is clamped between the cylindrical bearingsurface 41 and the cylindrical support piece 43, the use of only onebolt 44 does not lead to the chuck claw 50 rotating around the bolt 44.Also, since a slit 53 is disposed to allow the bolt 44 to be inserted,there is no need to detach the support piece 43 or the bolt 44 from thearms 15L, 15R when removing or attaching the chuck claws 50. Thus, thechuck claws 50 can be attached and removed easily. When the bolt 44 isremoved, the pull from the coil spring 45 draws the support piece 43away from the bearing surface 41, thus making mounting of the attachmentbase 52 of the chuck claw 50 even easier.

Since the chuck claws 50 are mounted inward from the arms 15L, 15R, thereaction from the force involved when the chuck claws 50 grasp thebottle BT can be applied to the arms 15L, 15R and not to the bolt 44.This is useful in maintaining the rigidity of the attachment section ofthe chuck claws 50. The slit 54 toward the grasping section 51 can beused to insert a tool (wrench) for manipulating the bolt 44, so even ifthe chuck claw 50 is attached to one of the arms 15L, 15R, the chuckclaw 50 for the opposite arm 15L, 15R can be easily attached or removed.The slit 54 is needed because the threaded hole 42 is sloped. The reasonfor providing the slope is as follows.

Securing the chuck claw 50 firmly requires that an adequate threadingdepth be provided for the bolt 44. However, reducing the pitch at whichthe chuck devices 5 are arranged along the perimeter and increasing thenumber of chuck devices 5 that can be attached to the wheel 6 requiresreducing the thickness of the chuck bearing 40 as much as is possiblewithout losing strength. As a result, orienting the threaded hole 42 tobe perpendicular to the chuck bearing 40 will not provide adequatethread depth. On the other hand, since the arm shafts 16L, 16R aredisposed behind the chuck bearings 40, forming the threaded holes 42from the bearing surface 41 along the reference line CL will not provideadequate length for the threaded hole 42. By extending the threaded hole42 diagonally outward from the bearing surface 41, it is possible tomaximize the length of the threaded hole 42 within the restricted space.

Furthermore, since the grasping section 51 is divided into upper andlower sections by the slit 54 of the chuck claw 50, the grasping section51 can be formed with different shapes above and below the slit 54 tomatch the shape of the bottle BT. Also, when the chuck claw 50 is formedfrom metal such as stainless steel, adequate rigidity can be providedfor the grasping section 51 even if it is thin, and more elasticdeformation is possible as well. As a result, the chuck claw 50 can beelastically deformed even when grasping bottles BT having differentdiameters as shown in FIG. 3. Thus, the chuck claws 50 can handlebottles BT with different diameters without requiring the chucks 50 tobe switched. Of course, it is also possible to switch the chuck claws50.

In the embodiment described above, the base 10, the arm shafts 16L, 16R,the top plate 14, and the post 32 form a supporting structure. Theroller shaft 17, the first roller 18, and the second roller 31 form thefirst drive section. The lever 22, the cam shaft 21, the arm drive cam25, and the first roller 18 form a motion input mechanism. The secondroller 31 and the cam surface 30 form a coupling mechanism. The presentinvention, however, is not restricted to the embodiment described above,and various different implementations are possible. For example, in thechuck device 5, it is possible to have multiple vertically arrangedlevels of chuck claws 50. Two or more pairs of arms 15L, 15R can beprovided in vertically arranged levels, with one or more chuck clawsbeing attached to each arm. When multiple vertically arranged levels ofthe chuck claws 50 are to be provided, it is preferable to optimize theshape of the grasping sections 51 of the chuck claws 50 to match theshape of the bottle BT where it will be grasped by the chuck claws 50.It is also possible to provide a freely rotatable roller at the innerside of the chuck claws 50, thus allowing the bottle BT to spin whilebeing grasped by the chuck claws 50 by way of the roller. This type ofstructure is suited for cases such as when the bottle BT is to berotated during the inspection step.

The biasing mechanism for the arms 15L, 15R is not restricted to thecoil springs 33, 35, and other structures can be used. FIG. 16 throughFIG. 20 show another embodiment in which a different biasing mechanismis sued. Elements that are the same as those from the embodiment shownin FIG. 1 through FIG. 15 are assigned like numerals and correspondingdescriptions are omitted.

In the embodiment shown in FIG. 16 through FIG. 20, the pair of armshafts 16L, 16R project upward from the top plate 14. To the outerperimeter of the projected sections 16 a are fitted torsion coil springs55, serving as a biasing mechanism, by way of bushes 16 b. The upperends of the arm shafts 16L, 16R are connected to each other by way of aconnecting plate 56 and bolts 57. On the lower surface side of theconnecting plate 56, a block 58 used as a spring peg is secured with abolt 58 a. The tightening force from the bolts 57 is received by the topplate 14 by way of the bushes 16 b, and this results in the arm shafts16L, 16R being supported between the top plate 14 and base 10, servingas a supporting structure.

As shown in FIG. 18 and FIG. 19, a pair of arms 55 b, 55 c are mountedon each arm shaft 16L, 16R by hooking one arm 55 c to the block 58 andthe other arm 55 b to pins 15 d disposed on the arms 15L, 15R whilekeeping the pair of arms 55 b, 55 c slightly open. The opening up of thearms 55 b, 55 c causes the elastic restoring force generated in a coilsection 55 a to bias the arms 55 b, 55 c toward each other (indicated bythe arrow A in FIG. 17), and this results in the arms 15L, 15R alsobeing biased in the direction that closes the chuck claws 50.

By using the torsion coil spring 55 as a biasing mechanism in thismanner, there is no need to extend the arms 15L, 15R behind the armshafts 16L, 16R or to provide the spring bearing hole 15 a (FIG. 9) orthe spring bearings 15 b, 15 c (FIG. 3) for the coil springs 33, 35.Thus, the rear ends of the arms 15L, 15R only extend to where they fitthe arm shafts 16L, 16R, and the post 32 is eliminated is as well. As aresult, the shape of the arms 15L, 15R is simplified and the number ofparts is reduced. As FIG. 19 shows, the torsion coil spring is arrangedsymmetrically relative to the reference line CL. Thus, the arms 15L, 15Rcan be biased symmetrically, and the symmetry of their operations can beimproved.

As FIG. 16, FIG. 19, and FIG. 20 show, the shortening of the arms 15L,15R and the elimination of the post 32 and the coil springs 33, 35creates space behind the roller shaft 17. The cam shaft 21 is extendedupward to fill this space. The upper end of the cam shaft 21 isconnected to the top plate 14 using a bolt 59. As a result, both ends ofthe cam shaft 21 are supported, and flexure of the cam shaft 21 can berestricted more than in the structure shown in FIG. 5.

Although the embodiments above use a bolt as a tightening mechanism,tightening means is not restricted to this. For example, as shown inFIG. 21, a rod 100 can be mounted using the threaded hole 42, and aspring 101 can be attached in a compressed state between an enlargedsection 100 a and the support piece 43. This allows the rod 100 and thespring 101 to be used as a tightening mechanism.

The chuck device of the present invention is suitable for use with astar wheel device, but the present invention is not restricted to thisand can be used in different types of conveyor devices in whichcontainers need to be grasped. Also, the chuck device of the presentinvention is not restricted to a structure in which a pair of arms isopened and closed to grasp an object such as a container. The presentinvention can use different types of chuck devices. For example, insteadof or in addition to having arms open and close, it is also possible tohave a chuck device with arms that slide to perform a grasping action.Chuck claws can be attached to the arms according to the presentinvention in this case as well. The attaching of the chuck claw to thearm according to the present invention can be implemented for caseswhere a single arm performs a grasping action as well.

With the first chuck device and conveyor device according to the presentinvention as described above, the motion of an operation member is firsttransmitted from a first drive section to an arm, the arm is rotated,and this rotation is transmitted to a second drive section by way of acoupling mechanism. By changing the modes in which motion is converted,the degree of freedom for the operations of the arms can be increased.Also, since everything from the operation member to each of the arms isformed from mechanical mechanisms, the operations are precise andreliable and higher conveyor speeds can be handled. Furthermore, byusing cam mechanisms for the motion input mechanism and the couplingmechanism simplifies the structure and provides further improvements inreliability.

Also, with the second chuck device and conveyor device according to thepresent invention, simply manipulating a tightening mechanism, e.g., abolt, allows the chuck claws to be attached and removed and alsoprevents the chuck claws from rotating. Thus, the chuck claws can beeasily attached and removed. In particular, with conveyor devices thatuse multiple chuck devices, the number of steps involved in attachingand removing the chuck claws can be significantly reduced.

Having described preferred embodiments of the invention with referenceto the accompanying drawings, it is to be understood that the inventionis not limited to those precise embodiments, and that various changesand modifications may be effected therein by one skilled in the artwithout departing from the scope or spirit of the invention as definedin the appended claims.

1. A chuck device for containers comprising: a supporting structure; apair of arms rotatably supported on said supporting structure by way ofa pair of arm shafts, chuck claws for grasping a container beingdisposed on ends of said pair of arms that open and close in tandem witha rotation around said arm shafts; and an operation member capable ofbeing externally operated; wherein: inward from said pair of arms isdisposed a first drive section capable of integrally rotating aroundsaid arm shaft of a first arm and being integral with said first arm,and a second drive section disposed further toward said end of said armthan said first drive section and capable of rotating integrally aroundsaid arm shaft of a second arm and being integral with said second arm;a biasing mechanism which biases said pair of arms around said armshafts in a direction of closing said ends of said arms; a motion inputmechanism disposed between said operation member and said first drivesection which converts motion accompanying external operation of saidoperation member to a rotation motion of said first drive sectioncentered around said arm shaft; and a coupling mechanism disposedbetween said first drive section and said second drive section whichconverts rotational motion of said drive section around said arm shaftto a rotational motion of said second drive section around said armshaft.
 2. A chuck device as described in claim 1 wherein said motioninput mechanism comprises a cam mechanism to convert a motion of saidoperation member to rotation motion of said first drive section.
 3. Achuck device as described in claim 2 wherein: said cam mechanism of saidmotion input mechanism is equipped with an arm drive cam supported bysaid support structure to allow rotation around a cam axis line parallelto said arm shaft, a cam surface being formed on an outer perimeter ofsaid arm drive cam; said arm drive cam is disposed opposite from saidsecond drive section relative to said first drive section; such thatsaid arm drive cam being rotated by operation of said operation memberfrom outside; as said arm drive cam rotates, said cam surface of saidarm drive cam moves back and forth between a position where said firstdrive section is pushed out toward said second drive section and aposition where said first drive section is retracted to an opposite sidefrom said second drive section.
 4. A chuck device as described in claim3 wherein a first roller that comes into contact with said cam surfaceof said arm drive cam is disposed on said first drive section.
 5. Achuck device as described in claim 3 wherein: a roller shaft parallel tosaid arm shaft is disposed on said first drive section; and on saidroller shaft, there is disposed a first roller coming into contact withsaid cam surface of said arm drive cam, and a second roller coming intocontact with said second drive section.
 6. A chuck device as describedin claim 3 wherein a support section is disposed on said cam surface ofsaid arm drive cam to support said first drive section at said positionpushed out toward said second drive section.
 7. A chuck device asdescribed in claim 1 wherein said coupling mechanism comprises a cammechanism to convert rotation motion of said first drive section torotation motion of said second drive section.
 8. A chuck device asdescribed in claim 7 wherein said cam mechanism of said couplingmechanism is equipped with a cam surface disposed on said second drivesection and coming into contact with said first drive section.
 9. Achuck device as described in of claim 1 wherein said biasing mechanismincludes a spring disposed between said support structure and saidsecond arm and biasing said second arm so that said chuck claws arebiased in a closing direction.
 10. A chuck device as described in ofclaim 1 wherein said biasing mechanism includes torsion coil springs oneach of said pair of arm shafts to bias said pair of arms so that saidends are biased in a closing direction.
 11. A chuck device as describedin claim 3 wherein: said biasing mechanism includes, torsion coilsprings disposed on each of said pair of arm shafts to bias said pair ofarms so that said ends are biased in a closing direction; and both endsof a cam shaft rotatably supporting said pair of arm shafts and said armdrive cam are supported by said supporting structure.
 12. A conveyordevice for containers comprising: a chuck device as described one ofclaim 1; and a mobile body moving said support structure of said chuckdevice along a predetermined conveyor path.
 13. A conveyor device asdescribed in claim 13 wherein a plurality of said chuck devices aredisposed on said mobile body along said conveyance path.
 14. A conveyordevice as described in claim 12 or wherein an operation section isdisposed along said conveyance path that comes into contact with saidoperation member when said chuck device moves.
 15. A conveyor device asdescribed in claim 14 wherein said operation section includes a movablesection capable of moving between an active position, where saidoperation section is in contact with said operation member and operatessaid operation member, and a stand-by position away from said operationmember.
 16. A conveyor device as described in claim 15 wherein saidmovable section is driven by an electrical servo motor between saidactive position and said stand-by position.
 17. In a chuck devicewherein a chuck claw is removably mounted on an end of an arm driven toperform a grasping action, a chuck device wherein: a cylindricallyindented bearing surface is disposed on said arm; a holding pieceequipped with a cylindrical outer perimeter surface curved along saidbearing surface is disposed on said bearing surface using a tighteningmechanism; and an attachment base curved along said bearing surface andcapable of being inserted between said support piece and said bearingsurface disposed on said chuck claw.
 18. A chuck device as described inclaim 17 wherein said tightening mechanism comprises a bolt.
 19. A chuckdevice as described in claim 18 wherein a slit is formed on saidattachment base of said chuck claw to allow said bolt to pass through.20. A chuck device as described in claim 18 wherein: a chuck bearing isdisposed on said arm to receive reaction generated on said chuck clawduring said grasping action; said bearing surface is formed to connectwith a side of said chuck bearing section that comes into contact withsaid chuck claw; said bolt is set up to attach to said bearing surfacein such a direction that, going toward a rear end of said arm, said boltextends from said bearing surface toward a back surface relative to aside of said arm in contact with said chuck claw.
 21. A chuck device asdescribed in claim 20 wherein: an arm shaft rotatably supporting saidarm is disposed behind said bearing surface; and said bolt is screwed inbetween said bearing surface and said arm shaft.
 22. A chuck device asdescribed in claim 20 wherein: left and right arms are disposed;
 22. Achuck device as described in claim 20 wherein: left and right arms aredisposed; a bearing surface is disposed inward from each arm; said boltspass through said support pieces from inward of said arms and arescrewed into said arms; and slits are disposed at ends of said chuckclaws to allow insertion of a tool used to manipulate said bolts.
 23. Achuck device as described in claim 22 wherein a spring mechanism isdisposed between said support pieces attached to said bearing surfacesof said arms to draw said support pieces toward each other.
 24. A chuckclaw wherein: a grasping section performing grasping actions is formedon a first end; and an attachment base curved to form a cylindricalsurface is formed on a second end.
 25. A chuck claw as described inclaim 24 wherein a slit extending in a perimeter direction of acylindrical surface defined by said attachment base is disposed on saidattachment base.
 26. A chuck claw as described in claim 24 or wherein aslit that divides said grasping section along a direction of an axis ofa cylindrical surface defined by said attachment base is formed on saidgrasping section.
 27. A conveyor device comprising: a mobile bodycapable of pivoting around a predetermined center; and a chuck device asdescribed in of claim 17; wherein a plurality of said chuck devices aredisposed along an outer perimeter of said mobile body.